CHULA VISTA, CA—Last fall, the U.S. Olympic Training Center in Chula Vista unveiled its brand new threeacre BMX developmental track, carefully designed after the Beijing Olympic track. Shortly thereafter, it played host to the UCI BMX Supercross World Cup. Quiet Voice Audio of Fallbrook, CA, took top honors with the installation of the facility’s sound system, consisting of 14 distributed QSC Audio K-10 active loudspeakers linked by a highly unique wireless audio distribution method based on Shure’s PSM 700 personal in-ear monitoring system.

What made the project especially challenging for the Quiet Voice Audio crew was that the facility is devoid of conduits for hard-wired cable runs and balanced audio feed lines. To make matters worse, there are only three electrical outlets for the entire facility.

With little to no hope of developing a totally hard-wired distributed system plan, Quiet Voice Audio’s Jon Bart decided wireless was the solution. “It was only logical,” he said. “Why not use UHF-FM to get our signals across some of the distances involved, and never mind the need for loudspeaker lines? We wanted to see how far we could push the envelope distance- wise with full quieting.”

Quiet Voice decided to take a trailblazing step and use a Shure PSM 700 personal in-ear monitoring system in a unique way. Each remote QSC Audio K-10 loudspeaker is outfitted with a wireless receiver installed in a customized solid waterproof Pelican box mounted to the cabinet. The box was outfitted with a Lemo connector for an antenna connection, a TRS 3.5mm connector to manage audio output, and a Shure PS9US 9V battery eliminator with a female 9V terminal clip added. The PSM 700 receiver was attached to the side of one of the selfpowered QSC K-10 loudspeakers distributed on the opposite side of the track facing the control tower. Using Shure paddle antennas at the receiver and transmitter end in the tower, Quiet Voice took the wireless signal received at the single loudspeaker location on the other side of the track and fed it to eight of the 14 loudspeakers via standard balanced lines. The remaining six loudspeakers near the control tower were wired with conventional cabling.

The wireless audio distribution system allowed Quiet Voice Audio to push the envelope in distance with full quieting and audiophile fidelity, providing a substantial increase in facility sound coverage. Additionally, the utilization of the wireless system to distribute the signal to the QSC Audio KSeries loudspeakers allows for future system growth at a minimal expense.

During the UCI BMX Supercross World Cup, the QSC Audio sound system delivered impeccable audio performance from the Pledge of Allegiance and National Anthem to the narration of the Navy SEAL Leap Frogs Parachute Team which dramatically descended onto the field during the opening ceremony, to the canned and live music and announcements, all of which was heard loud and clear over the excited crowd.

“QSC Audio’s new K-Series active loudspeaker line is impressive—1,000 watts per enclosure, biamped, lightweight, easy storage footprint, very efficient use of available AC power, and, most importantly, accurate, wide sound coverage,” Bart said. “This was a win-win project where we got to think outside the box and through incorporating incredible off-the-shelf and cost-effective products we delivered an innovative sound system to a very appreciative client.”